US vs Iran
more effective ability to attack naval forces, tanker traffic, offshore facilities, and targets along the Southern Gulf coast. It is this "focused poverty" that makes Iran potentially dangerous in spite of its relatively low level of arms imports and the obsolescence or low quality of much of its order of battle.” 
As I mentioned earlier, any US attack on Iran will start with a comprehensive air attack. This attack will have to neutralise two components of the Iranian defences: Iranian air force and the land-based air defences. We shall now briefly examine Iranian Air force and land-based air defences.
Iranian Air Force
It is extremely difficult to determine the operational capabilities of the Iranian Air Force. We can of course presume that the United States, with the help of its spy satellites, already knows the numbers, types and the operational capabilities of the Iranian aircrafts. But for the rest of us, we have to dig into military journals, news reports and search through internet sites. The following list presented bellow is only a very conservative estimate (on the low side) and by no means reflect the true capability of the Iranian Air force. According to some reports the Iranians have upgraded the following aircraft in terms of weapons systems and avionics with the help of Russia and China;
MiG-23 (New weapons systems to include AA-12 missiles, smart bombs and effective RWR and flight refuelling. It also has data-link and much improved radar system);
Dr. Abbas Bakhtiar